That stuff is highly addictive. Honest to god, if he suggested it, most likely he takes it too. Get out of there, his expectations are based around people abusing speed, which means he basically expects some unhealthy output. Remember kids, all drugs work, until they don’t. You can always take more I guess.
If you find yourself needing to take more, please talk to your health professional. Help is available.
This conversation happens in reality all the time, for millions of adults that take it for their work.